Got a noisy bedroom? You might be at a greater risk for weight gain, according to a new study conducted at the Swedish medical university Karolinska Institute.
As urban communities grow and rural ones shrink, noise pollution is a growing problem. Traffic and other transportation-associated noise are sometimes to blame for sleep disturbances, which in turn may contribute to weight gain, cardiovascular risk and a host of other potential health problems.
"Traffic noise may influence metabolic and cardiovascular functions through sleep disturbances and chronic stress," lead study author Dr. Andrei Pyko told Australian Associated Press. "Sleep disturbances may affect immune functions, influence the central control of appetite and energy expenditure as well as increase circulating levels of the stress hormone cortisol."
Pyko's study, which was published in the medical journal BMJ, looked at 5,075 Swedish residents who were exposed to road traffic, railways and aircraft noise over the course of four years. Controls accounted for mitigating factors, like socioeconomic status and occupation, he told HuffPost. The results showed that people who were exposed to any of these noises had more belly fat, which is linked with higher heart disease and cancer risk. That risk factor doubled for people living with all three noises.
It makes sense that if traffic noise is disrupting a person's sleep, they're at higher risk for weight gain. According to a 2012 review of 18 studies on sleep and appetite, bodies getting six hours of sleep or less start producing more gherlin, otherwise known as the "hunger hormone." So even if a person is clocking seven to eight hours of sleep every night, it's probably not high quality if it's constantly disrupted.
Of course, more research needs to be conducted in order to actually draw conclusions about whether or not traffic noise causes weight gain; the new Swedish study simply found an association between the two. But according to The Independent, researchers said that because high cortisol levels are linked with belly fat, the findings make a lot of sense.
“This may explain why the effects of noise were mainly seen for markers of central obesity, such as waist circumference and waist-hip ratio, rather than for generalized obesity, measured by BMI," the researchers explained.
Worried about your noisy bedroom? Here are 7 tips for blocking out sounds.